This invention relates to endodontic tools, and in particular, to a cannula for a combined irrigator and vacuum device. Although the cannula and the combined irrigator/vacuum device to which it is connectable are described for use with endodontic procedures, it will be apparent that they can be used for other dental or medical procedures as well.
Following tooth maturation, the dental pulp is harbored within the structural elements of the tooth. Frequently, and for a variety of reasons, the pulp is irreversibly injured, resulting in inflammatory and infectious conditions which often adversely affect the tooth and its supporting structures. Clinically, as an alternative to extraction, root canal treatment is performed and ideally is directed towards the elimination of pulp, bacteria, and related irritants from the root canal system, followed by three-dimensionally filling the root canal space with an inert, biocompatible, dimensionally stable, filling material, such as gutta percha. Ideally, the obturation procedures will fill not just the main canal, but the fins, webs, anastomoses, lateral canals, and all portals of exit between the root canal system and the tooth's attachment apparatus.
Central to a successful endodontic (or root canal) treatment has been the use of chemical reagents during mechanical root canal shaping procedures to completely clean all aspects of the root canal system. The chemicals used to enhance canal debridement and disinfection during cleaning and shaping procedures potentially reach all aspects of the root canal system. The most popular chemicals currently used during canal preparation to actively assist in cleaning and disinfecting include bleach, hydrogen peroxide, and chelating agents. Clinicians irrigate with a 2%-5% solution of a clear, pale, greenish-yellow strongly alkaline solution of sodium hypochlorite (NaOCl), a 17% solution of and ethylenediaminetetracetic acid (EDTA), or other final rinse solutions. These solutions are used individually or in combination.
During canal preparation, a solution of NaOCl is liberally irrigated into the root canal space where its solvent action facilitates the digestion and removal of pulp, bacteria, viruses, spores, endotoxins and other irritants generated by microorganisms. This solution has the potential to circulate, penetrate and, hence, clean into all aspects of the root canal space. However, studies have shown that even the most thorough use of sodium hypochlorite does not remove all the material from the root canal. The walls of a root canal are comprised of dentin, which structurally contains thousands of dentinal tubules per square millimeter. Instruments used to cut dentin and shape a canal, in combination with organic substrates, forms a cocktail of debris. Dentinal mud, pulpal tissue, bacteria, and other related irritants have been consistently visualized histologically in the dentinal tubules and various aspects of the root canal systems following root canal preparation procedures. Thus, after shaping procedures, the root canal is frequently covered with a film of debris, described and referred to in the literature as a “smear layer.” Recently, biofilms have been reported within the environment of the root canal space. Biofilms form from a gelatin-like, sticky polysaccharide mass and harbor bacteria. As such, cleaning refers to those clinical procedures that encourage debridement, removal of the smear layer, and the elimination of biofilms.
After cleaning and shaping, the root canal has been traditionally filled with gutta percha and a sealer. Failure to adequately clean the root canal system can compromise the filling and sealing of the root canal system. If obturation is incomplete then the root canal space is predisposed to bacterial leakage and failure. Post-treatment failures attributable to leakage are common and require endodontic retreatment of the tooth or extraction. Therefore, to improve clinical success, irrigating methods must be developed to promote safe and three-dimensional cleaning of a complex anatomical space. Certainly, one of the most intriguing frontiers of complete endodontic cleaning is the reagents, their delivery, and their method of activation.
Flushing of the root canal is generally accomplished with an irrigating syringe which is utilized to inject fluids, as mentioned above, into the root canal space. During the cleaning process, dentinal debris, pulpal tissue, bacteria when present, and their related irritants are moved into solution during the preparation of any given root canal. As can be appreciated, this dirty solution must be removed from the root canal as part of the cleaning process, and prior to filling and sealing of the prepared root canal. Removal of the solution is typically accomplished with a vacuum which is separate from the irrigating syringe. The definitive drying of the preparation is accomplished by wicking residual moisture from the canal using appropriately sized paper points. However, in the time that it takes to switch from the irrigating syringe to the vacuum device, debris, bacteria, and other elements that the practitioner desires to remove oftentimes settle back into the canal, making removal of this debris more difficult.